Naltrexone improves immune functions and spatial memory of ovariectomized rats with alcohol intake

Estrogen deficiency and excessive alcohol intake are associated with numerous adverse effects on immune functions and cognitive abilities. There is lots of evidence for the role of cytokines in the functions of the central nervous system like emotions, learning and memory. The aim of the present study was to investigate the effects of the opioid antagonist naltrexone on IFN-γ serum levels and spatial memory of ovariectomized (OVX) rats with repeated alcohol intake. Female Wistar rats (200–200 g) were ovariectomized and randomly divided in four groups: 1 – “control” (physiological solution 1 ml/100 g p.o. for 4 weeks after OVX); 2 – “alcohol” (ethanol 30%, 1 ml/100 g, p.o. for 4 weeks after OVX); 3 – “alcohol+naltrexone” (ethanol 30%, 1 ml/100 g, p.o. for 4 weeks after OVX and naltrexone 2.5 mg/kg, i.p. for 3 weeks after OVX); 4 – “naltrexone” (naltrexone 2.5 mg/kg, i.p. for 3 weeks after OVX). Our results suggested a correlation between IFN-γ levels and learning and memory abilities of the experimental rats. Moreover, we demonstrated that naltrexone reduced the adverse effects of OVX and excessive ethanol on IFN-γ levels and cognitive performance. Our data suggest that naltrexone may have beneficial therapeutic effects on immunodeficiency and emotional and intellectual deficits in women with estrogen insufficiency and excessive alcohol intake.